Review on Development of Seed Dormancy Mechanisms

Seed dormancy of many plants is a kind of specialization that has adapted them to the environment and to continue to live,and also is a evolutional stability strategy.Seeds of wild plants,especially,which live temperate zones,have very long and deep dormancy.There are lots of concepts of seed dormancy,and these concepts induce many theories and hypotheses and models.Husk obstruction,morphological embryo hypoplasia,physiological after-ripping,and chemical inhibitors in seeds all make seeds to be dormant.According to various criterions,seed dormancy could be classified into various categories,but dormancy was generally classified into exogenous,endogenous,and combinational dormancy.Causes of dormancy were complicated,and the seeds of different plant species had different characteristics of dormancy.There was variation in seed dormancy among the seeds from the same species because of various populations and individuals,periods for collecting and locations of mother plants.Moreover,there was difference among the seeds from the same fruit.Seed dormancy were generally quantitative traits influenced by a large number of genes including nuclear and plasmagene.Seed dormancy benefited regulating spatio-teporal distribution of seed germination.Studies on characteristics of seed dormancy and mechanism and on releasing methods of dormancy are very useful to agricultural production and plant-diversity conservation.This report summed up the research advances of mechanisms of seed dormancy in recent years.